Steering wheel or other articles



vF'b.1'fs,`19`43.` 'JjsgmAaY' 2,311,317

y STEERING WHEEL OR OTHER ARTICLES 'Filed June 1, 1939 4 sheets-sheet 1ATT/Q/VEYS Feb. 16, 1943.

J. B. TEGARTY STEERING WHEEL OR OTHER ARTICLES Filed June l, 1939 4Sheets-Sheet 2 /NVENTO Feb, 16, 1943. B TEGRTY 2,311,317

STEERING WHEEL OR OTHER ARTICLES Filed June 1, 1959 .14 sheets-sheet 3is j Feb. 16, 1943.

Jf B. TEGVARTY` STEERING WHEEL rR OTHER ARTICLES Filed June 1, 1959 `4Sheets-Sheet- 4 INVENTOR Patented Feb. 16, 1943 UNHTED STAT STEERINGVVHEEIr iOR OTHER ARTICLES .lohn B. Tegarty, Buffalo, N. Y., assigner toSterling Injection Molding, Inc., Buffalo, N. Y.

Application June 1, 19139, seria-1m. 276,855

1 Claim.

This invention relates to improvements in articles formed at least inpart of a metal and in part of a thermoplastic or a thermo-settingmaterial. This application is in part a division of my pendingapplication Ser. No. 239,137, filed November 5, 1939.

Thermoplastic materials, such for example as cellulose acetate, areplasticized by heat and forced under high pressure .into a mold cavityin which the material iscooled' and-solidified. Machines now availablefor use in connection with this type of molding are limited in capacitybecause of the characteristics of thermoplastic materials and because ofconditions under which the molding must take place, so that only arelatively small quantity of thermoplastic material can be extruded andmolded at one time.

One of the objects of this invention is to produce an article includingmore plastic material than can be molded by one operation of themachine, by forming the plastic material thereon sectionally andprogressively.

I have also found that in the case of'articles having relatively largeparts yof plastic material molded in contact with metals, the plasticmaterial will crack When the article is subjected to changesintemperature. vThis cracking is due to the difference in coefficientsof expansion of plastic material and metals@v It alsosometimes happensthat in articles, such as steering Wheels, having a metal frame or coresurrounded by plastic material, the metal frame or core will twist orwrithe, which also causes the plastic material to crack or split.

It is, consequently, a further object of tln's invention to provide anarticle having 'a metal frame or core With a covering of plastic moldedmaterial formed in sections having joints or connections at their endswhich permit the metal frame or core tochange its form without producingcracks or splits in the plastic molded material. Another object of `thisinvention is to provide a steering wheel having a .metal core aboutwhich a plastic molded material is applied in sections, the ends of eachsection being free to move to a limited extent relatively to other partsof the wheel. Another object is to provide a Wheel of this kind in whichthe ends of each section intert with adjacent parts of the wheel toprovide a limited movement of the ends relativelyv to such adjacentparts,4

A'further object of the invention isto provide articles of improvedconstruction which can be formedlby'progressively sectionally moldingthermoplastic material thereto. A further Objectis to provide articlesof improved construction including a preformed article havingenlargements arranged at intervals therein which may cooperate with acavity in a mold to close the ends thereof and with the molded sectionsto secure these sections in the desired relations to the article.

Other objects of this invention will appear from the followingdescription and claim.

In the accompanying drawings:

Fig. 1 is a side elevation of a molding machine of improved constructionfor use in connection With a process embodying this invention andshowing an article embodying this invention being operated upon.

Fig. 2 is a fragmentary transverse sectional elevation thereof, on line2 2, Fig. 1.

Fig. 3 is a fragmentary longitudinal section thereof, on line 3 3, Fig.v2.

Fig. 4 is a fragmentary transverse section, on an enlarged scale, of anarticle formed in accordance with my improved process, the section beingtaken on line 4 4, Fig. 2.

Fig. 5 is a section thereof, on line 5 5y Fig. 4.

,Fig. 6 is a face View of another article embodying this invention andformed in accordance with my process.

Fig. 'i' is a section thereof, on an enlarged scale, on line 1 1, Fig.6.

Fig. 8 is a transverse section thereof, on line 8 8, Fig. 7.

Figs. 9 and 10 are respectively transverse and longitudinal sections ofa joint or connection between adjacent molded portions of anotherarticle formed in -accordance with my invention.

Fig. 11 is a plan view of a.steering Wheel of modified construction.

Fig. 12 is a fragmentary view, partly in -section, of a portion of therim, on an enlarged scale.

Fig. 13 is a plan View of still another modified form of steering wheel.

Fig. 14 is a fragmentary view thereof partly in section and on anenlarged scale.

Steering Wheelsand other articles having a metal core covered withplastic materials Were heretofore made in such a manner that the entirecovering was formed as a unitary piece, This, in-the case ofthermoplastic materials, necessitated the use -of a relatively largemachin-e capable of molding the entire covering of plastic material in asingle operation, or in the case of other plastic materials, relativelylarge presses were required to form the entire covering as a singleunitary piece.

`,In accordance With thisinvention, the Steering wheels or otherarticles are formed in such a manner that the molded plastic coveringmaterial may be applied to the base or metal core of the article inseparate parts or sections. This has the advantage that the article maybe formed on a much smaller machine, since only a small portion oi themolded plastic covering material need be applied to the article at onetime. My improved articles have the further very decided advantage inthat the danger of cracking Aor splitting of the coveringmaterial, dueto radically diierent coefficients of expansion and contraction of themolded plastic material and the metal, is eliminated. In the case of anarticle with a unitary covering, the covering will split or crack whenexposed to low temperatures, or

when the core twists or writhes. By forming the molded plastic coveringmaterial in separate sections, disconnected from each other at their Yends, the objectionable cracking or splitting of the covering materialis avoided, since the ends of the separate pieces or sections of thecovering material may move relatively to each other either in adirection toward or from each other to compensate for these differencesin expansion and contraction, or in a rotary direction relatively toeach other to compensate for twisting or writhing of the metal core.Itis not necessary in accordance with this invention that the severalsections of the covering material be successively formed or molded,since if a machine of suiiciently large capacity is available, thesections of the plastic covering material may be simultaneously molded,providing that the ends of the several sections of the covering materialare not integrally secured to each other.

The terms molded plastic material or molded plastics as herein employed,are intended to include not only thermoplastic and thermo-settingmaterials, but also rubber compositions which may be molded to form acovering for-a metal core.

Figs. 1, 2 and 3 show one form of molding machine for use in connectionwith the making of articles according to this "invention, the machineshown being forV use with extrusionY or injection molding. Thegreaterportion of this machine is of a standard construction asheretofore used, the machine being changed to enable the same tc producesome types of articles of relatively large dimension in accordance withthis invention. The machine shown in the accompanying drawings includesa base l5 provided with a pair of die supporting plates vII- andl I?suitably mounted on the machine, ,at least one of said plates beingmovable toward and from the other. The die plate I6, in the constructionshown, is connected by means of a plurality of toggle links I8 arrangedto be actuated by means of a plunger or piston arranged in a cylinderI9. When fluid under pressure is admitted into one end of the cylinderI9, the toggle links are moved toward and into dead center position formoving the die plate I6 toward the other die plate I1. 23 land 2|represent cooperating dies or molds of any-desired kind suitably securedto the die plates I6 and I'I, and 24 represents a passage formed in theldie or mold 2| through which heat softened or plasticized thermoplasticmaterial may pass vfrom a nozzle 25 to a cavity 26 formed in theadjacentfaces of the molds or dies. The nozzle 25 receives thermoplasticmaterial from a heating cylincler 23, the thermoplastic material beingeX- truded by means of a plunger 29,V shown in broken lines in Fig. 1,which is actuated by means of a piston (not shown) arranged in acylinder 30. 3l represents a hopper for thermoplastic material, fromwhich the material may be fed in necessary quantities into the heatedcylinder 28, when the plunger 29 is reciprocated. 32 represents a motorwhich operates suitable compressing means for supplying fluid underpressure to the cylinders I9 and 30, and 33 represents a plurality oftie rods or bars which connect a stationary frame member or plate 34 towhich one end of each set of toggle links I8 is pivoted, with anotherfixed part 35 of the machine located adjacent to the die plate I1. Thesetie rods serve to hold fixed parts of the machine in correct relation toeach other and prevent separation of the dies or molds due to vthe heavypressure of the thermoplastic material in the mold cavity. The machineas thus far described, is of standard and well known construction, andthis machine, as heretofore constructed, may be used in connection withthe manufacture of certain articles according to my invention.

In order to enable this machine to operate upon objects of a looped orannular form, such for example as steering Wheels, which are of greaterdiameter than the space between the tie rods 33, I have provided meanswhereby one or more of the straight tie rods may be replaced by othermeans for opposing the stresses resulting Vfrom the pressing of the diesor molds into contact. These means may be of any suitable form, forexample, a tie member 40 of arched form may be employed, the endportions 4I of which extend transversely to the body, portion and arearranged to be secured to the stationary machine parts 34 and 35 bymeans of short bolts 42. These arched tie members provide for a greatlyenlarged space transversely of the machine in which wheels, frames orlooped articles may be arranged, which extend beyond the dies or moldsof the machine, for reasons hereinafter more fully explained.Consequently, as clearly shown in Fig. 2, this construction readilypermits a comparatively large article, such as a steering well, to bepositioned so that a part thereof may-'be operated upon by a relativelysmall machine. Obviouslyother means for supporting or bracing themachine against the pressure exerted against employed.

It will be noted in referring to Figs.' 1 to H3 that the die used inconnection with my improved process is of such form as to cooperate atone time with a portion only of the article, and the article may beturned or advanced into another position in which another portion of thearticle is to be molded. 'Ihe die is also provided at the ends of thecavity 26 therein with suitable portions 46 which are formed to engageportions of the article to securely clamp the same in correct relationto the cavity-in the mold. In case of a Wheel, these parts of the moldmay be formed so as to engage the preformed metallic base or core A ofthe rim of the steering wheel, or if desired, the clamping parts of themold Vmay engage with enlargements or anchoring portions on the rim ofIthe steering 4wheel for securing the steering wheel in correct'relationto the mold, and preferably these enlargements also close the ends ofthe mold cavity. If desired, the ends of these enlarged portions may berecessed or otherwise formed so'as to provide parts into whichthermoplastic material may flow or the die plates may ber embed itselffor providing secure anchorages for the ends of the sections of thethermoplastic material, In-the construction shown in Figs. 1 to 5inclusive, the preformed wheel rim base or core A is provided withenlarged portions 41 arranged at 'the spokes a of the wheel. Theseenlarged portions may be formed of metal, in which case they may, forexample, be die cast on these portions of the wheel, or if desired, theenlarged portions may be made of thermoplastic material applied by meansof the machine described in molds or dies having a corresponding cavity,to portions of the rim of the wheel at the outer ends of the spokes. Inthe construction shown, the enlarged portions 41 also form separatingelements for the final thermoplastic sections and are provided withundercut or recessed end faces 49, but if desired, outwardly extendingparts may be provided for anchorages for the iinal thermoplasticmaterial applied to the Wheel rim.

In the use of this machine to form my improved articles, the dies ormolds are formed in such a manner that the mold cavity 26 is shaped toform a portion of the article, which in the case illustrated in Figs. 1to 5 is a steering wheel having a thermoplastic covering about all 0r aportion of the core A of the wheel rim. At the ends of the mold cavity26, the dies are so formed at the gripping portions 46 as to receive theenlargements 41 and securely grip them. This enables the dies to holdthe part of the core or base A in correct position with reference to thedie cavity 25 and the enlargements, consequently, also form closures forthe ends of the mold cavity.

After the two dies have been brought into engagement by means of thetoggle links I8 and cylinder I9, plasticized or semi-liquidthermoplastic material is forced into the die cavity through the passage24 in the mold until the cavity of the mold is completely lled and thethermoplastic material 50 enters into engagement with the end portions49 of the enlargements or separating elements 41, The thermoplasticmaterial is maintained under high pressure in the mold cavity, and sincethe mold is cooled by suitable means (not shown), the material willsolidify to form an envelope or sleeve around the wheel rim core Aextending from one enlargement 41 to the other. When the material hasbecome solidied by cooling, the pressure on the thermoplastic materialis interrupted and the die plate I6 is moved away from the plate I1 sothat the steering wheel with the molded section thereon may be removedfrom the dies and turned into another -position to have another portionof the preformed core A positioned in the mold cavity 26 in the samemanner as heretofore described in connection with the first portion ofthe wheel. The process is then repeated until the three portions of thewheel rim shown in Figs. 1 to 5 are covered with the thermoplasticmaterial.

If the enlargements or separating elements 41 on the wheel are to bemade of a thermoplastic material, the depressions or recesses 49 in theends of the enlargement may be omitted or replaced by correspondingoutwardly extending portions and the enlargements 41 may be molded onthe wheel in the same or similar machine provided with another set ofdies shaped to form the enlargements 4-1. rIhe covering portions 50 canthen be progressively sectionally molded on the wheel rim in the samemanner as described.

While I have described the article as made by means of an injectionmolding machine of relatively small size, it will be obvious that thesections 59 of molded plastic material may be formed simultaneously on alarger machine, the sections being spaced apart to permit the spacingmembers 41 to be positioned between the ends of the sections 59. Thesections may also be formed one at a time, or all at once, in acompression molding machine, of thermo-setting material or of a plasticrubber composition. The iinished wheel will then have the advantage thatwhen exposed to low temperatures, the sections may contract to a greaterextent than the core A, so that the ends of the sections may move awayfrom the enlargements or spacing members 41 of the core to a slightextent, thus avoiding cracking of the covering material. Theconstruction described also permits a rotary or twisting movement of theends of the sections 59 relatively to the enlargements or spacers il incase the core A twists or writhes.

In Figs. 6 to 8 inclusive, I have shown a wheel of modified constructionmade in a similar manner. In this wheel, the mold cavity is so formedthat the progressively formed sections of molded plastic material 52terminate at points approximately intermediate between the spokes. Informing these sections, the gripping portions 45 at the ends of the moldcavity are formed to engage the preformed wheel rim core A and thus formthe ends of the sections 52. These ends may, for example, be providedwith annular parts or projections 53, as clearly shown in Fig. 7. Themold cavity may also be provided with a portion which forms the moldedplastic material at 54 around the outer ends of the spokes a., Themolding of the three sections 52, is effected in a manner similar tothat described in connection with the forming of the sections 59, exceptthat these sections will not have their ends abutting againstenlargements on the wheel rim. Instead the sections 52 will be spacedfrom each other. After the sections 52 have been molded on the wheel,either progressively or simultaneously, the spaces between the ends ofthe sections can be lled with inserts of any suitable or desired kind.For example, semicircular inserts 55 and 55 may be provided which ntinto the spaces between adjacent sections 52 and telescopically engagethe annular projections 53. These semi-annular inserts may be made ofmetal or of a molded plastic material and secured in place by means of abolt or rivet 51 extending,

through the same and through a hole in the core A. The semi-annularinserts may also be made cf thermoplastic material which may be readilycemented in place by wetting the inner faces of the inserts and the endsof the sections 52 with acetone or other solvent for the thermoplasticmaterial. In this manner, the inserts can be securely cemented in placeto the ends of the sections 52 and to each other, and if desired, labolt 51 may also be used, the head of which could, for example, bemolded into one of the semi-annular inserts.

It is, of course, also possible to produce the article shown in Figs. 6to 8 by first applying the parts 55 and 56 to the base or core A andthen molding the sections 52 tothe rim as described in connection withFigs, 1 to 5.

The construction shown in Figs. 6 to 8 has the same advantages as thatdescribed in connection with Figs. 1 to 5. If the spacing membersl 55are applied `to the core A before the sections E52 are molded thereon,and if both spacing members and sections are formed of thermoplasticmaterial, the ends of the sections 52 will not become integrallyconnected to the spacing members, since the hot plasticizedthermoplastic material of the sections, when forced into contact withthe cooler :and solidified thermoplastic spacers 55, will not bond orfirmly unite therewith. Consequently, the ends of the sections 52 oncontracting, can separate from the spacing members 55 or can movecircumferentially relatively thereto, to prevent cracking or splittingof the covering material.

In Figs. 9 and 10, I have shown a modified form of this invention whichis applicable either to a rim of a steering wheel or to a straight orbent rod which may be employed as a core to which the molded plasticsections may be applied. In this case, spacing sleeves or ferrules 60are provided which may be used as enlargements or separating elementsfor the sections, to cooperate with the gripping parts of a mold andwhich may form the ends of the mold cavity. These sleeves are preferablyundercut at their ends to form a telescopic connection with the moldedmaterial and may be provided on their inner surface with a series ofgrooves or keyways 6| and 62 extending from the outer ends of the sleeveor ferrule Si) into proximity to the middle portion 63, which is formedfor snug or tight engagement with a base or core 64, which may be therim of a steering wheel or a straight or otherwise shaped rod.

It will be obvious that after these sleeves or ferrules are correctlyand equally spaced on the core or base 64, the molding of the sections65 of the plastic material may be progressively or simultaneouslyeffected in the same manner as heretofore described, the mold being soformed that the gripping portions 46 thereof cooperate with the sleevesor ferrules 6D to hold the core member 64 in correct relation to themold cavity and to `close the ends of the same. The hot plastic materialthen flows under pressure into the grooves or keyways 6| and 62 of thesleeves, which securely anchors the ends of the sections 65 and formstelescopic connections therewith. y

When straight or only slightly curved articles are formed on aninjection molding machine, it

will .be obvious that the machine may be used as heretofore constructedwith straight tie bars or rods in place of one or more arched tiemembers, as shown in Figs. 1 to 3. If, for example, a relatively longrod, bar, plate, or panel is to be molded, a corresponding mold isplaced into the machine and a prefabricated base to which the materialis to be molded may, if desired, be used in connection with such moldandpassed successively through the mold` to progressively mold sectionsof molded plastic material thereon. If the preformed article is providedwith enlargements which may be engaged by the mold at the ends of themold cavity, then the sections of molded material may be formed betweenthese enlargements, as indicated in Figs. 1 to 5, 9 and 10. If thepreformed article has no enlargements, the plastic material may bemolded on the preformed article by molding each section thereof to anedge or end of a preceding section. As another alternative, the mo-lditself at the ends of the cavity therein may be formed with grippingportionsengaging the preformed article as described in connection withFigs. 6 to 8 inclusive, so that gaps are formed between the moldedsections, which may `be closed in any suitable manner, for example, bymeansof inserts of similar material which may be cemented or otherwisesecured to the article between sections of molded material. It is alsoan advantage that the inserts used in this manner may be of diiferentcolor, shade or texture than the main sections of the article and thismakes it possible to produce artistic and pleasing effects that cannotbe produced by processes in which the entire molded material is made inone piece. The variation in 'colors can also be produced by forming theenlargements 41 shown in Figs. l to 5 of molded plastic material of adifferent color from that of the sections 50.

In Figs. 11 and 12, I have illustrated a steering wheel somewhat similarto the one shown in Figs. 6 to 8, except that the spacing membersbetween molded sections of the covering material are of a differenttype. In this case, spacing members 10 are employed which are in theform of cylindrical sleeves made in one piece and these sleeves may beof a metal, of molded plastics, or of other materials. The requirednumber of these sleeves, three in the construction illustrated, areplaced on the wire or rod member from which the rim of the steeringwheel is made, before the ends of the rim are welded together, and thesesleeves 10 are then so positioned on the finished rim base or core 1|,Fig. l2, so that one of these sleeves is located between each set ofspokes 12. The molded plastic covering material 13 may be molded on thecore and about portions of the spokes 12 in any desired manner, forexample, by means of an injection molding machine as disclosed in Figs.1 to 3, or these sections may be formed of thermosetting material or ofa. rubber composition. In any case, the parts 10 are set incorrespondingly shaped parts of the mold, this being facilitated by thegrooves 14, which may be placed into engagement with correspondingbieads in the mold cavity to ensure a correct positioning of the spacingsleeve 10. In order to facilitate the movement of the spacing sleevesrelatively to the core 1|, it will be noted that the opposite ends ofthe sleeves are undercut, as indicated at 15, so that only the middleportion 16 of each sleeve bears against the core 1|. These recessedportions 15 also permit the molded plastic material to enter into thespaces between the recessed portions 15 and the core 1| to form atelescopic or overlapping joint between the spacing sleeves 10 and themolded plastic material 13. This wheel may be formed either byprogressivesectional molding of the plastic covering material on thewheel, or the several sections 13 of the covering material may besimultaneously molded in three separate sections, spaced apart by meansof the spacing sleeves 10. Consequently, in the case of contraction ofthe molded material 13 to a greater extent than the core 1 I, as wouldhappen when the wheel is subjected to low temperatures, the ends of theplastic material entering into the undercut portions 15 or abuttingagainst the spacing sleeves 1|) may withdraw to a slight extent from thepositions shown in Figs. 11 and l2, thus forming slight gaps 'betweenthe ends of the sleeves 10 and the molded plastic material 13, whichgaps become closed when the wheel is again subjected to highertemperatures. Also the twisting or writhing of the core 1| can be takenup by a slight rotary movement of the covering material ,13.relative tothe sleeves 10 and the adjacent end of another section of the coveringmaterial. v

In the construction shown in Figs. 13 and 14.

I have shown a steering Wheel having spokes 80 and spacer members 8|which may be of metal or of molded plastic or other suitable material,and which may also be applied to the base or core 82 of the rim of thewheel in a manner similar to the sleeves 'I0 shown in Figs. ll and l2,namely, by positioning them on the rim 82 before the two ends thereofare secured together, for example, by welding. In this construction, thespokes and the spacing members or sleeves 8| may be positioned on thecore 82 of the rim by means of shallow apertures or recesses 83 formedon the inner face of the core 82, into which the outer ends of thespokes may enter` The sleeves or inserts 8| may be of approximately Tshape, being provided with projections or tubular portions 84 extendingtoward the hub of the wheel and having internal threads S5. The spokes80 have correspondingly threaded portions adjacent to their outer ends.In assembling the Wheel, the spokes 80 are threaded into engagement withthe screw threads 85 and so positioned on the core 82 that the endsthereof enter the recesses 83. In this manner, the spacing sleeves 8|and spokes 80 will be accurately held in correct positions on the core.The inner ends of the spokes may then be suitably secured to the hubportion 86 of the steering wheel in any suitable or well known manner.

The ends of the spacing sleeves 8l may, if desired, be recessed orundercut to receive some of the molded plastic material, and the plasticcovering material 81 for the core 82 may be applied to the wheel in anysuitable manner, either by injection molding, or by pressure molding asin the case of thermo-setting materials or rubber compositions.Furthermore, if desired, the sections 81 of molded plastic material maybe either formed one at a time and in succession so as to permit the useof smaller machines or presses, or they can be formed in a singleoperation.

From the foregoing, it will be obvious that articles can be producedincluding a much larger quantity of molded plastic material than thenormal capacity of the machine on which the articles are formed. Sincethe cost of machines of this kind increases very materially as themachines increase in size and capacity, it will be obvious that articlesas herein described can be produced at a lower cost than heretoforepossible, sincethey can be formed by the use of smaller and lessexpensive machines. Also since the dies required for progressivesectional molding are smaller than those required for molding largearticles, it follows that the cost of producing such large articles inaccordance with my process is further decreased. It is also well knownthat smaller molds will cool much faster than larger molds, andconsequently, each molding operation on the small mold can be completedin a materially shorter time than an operation on a larger mold. In themanufacture of some types of articles, it is also more easily possibleto accurately mold the plastic material on a preformed article, sincerelatively small portions of the preformed metal article are conned in amold at one time, andsuch smaller portions can be more accuratelypositioned in a mold cavity than larger articles.

In addition to the use o-f my invention in connection with wheels orother circular objects, straight articles such as rods, panels or thelike, it will be obvious that frames or other looped articles may beproduced by progressively sectionally molding the same.

I claim as my invention:

A steering wheel including a rim having an annular metallic core andspokes secured at their outer ends to said core, said core having acovering formed mainly of sections of molded plastic material separatedfrom each other by spacers, the outer diameter and contour of saidsections and spacers being similar, said spacers being located on said'core between said spokes and having their ends in telescopic arrangementwith said sections but detached therefrom, to permit expansion andcontraction of said plastic material, said material covering theconnections of said spokes with said core.

J OHN B. TEGARTY.

